This invention relates in general to methods of manufacturing composite structural components and in particular to a pultrusion method of manufacturing a composite structural component for a vehicle.
Most land vehicles in common use, such as trucks, vans and automobiles, include a body and frame assembly which is supported on a plurality of ground-engaging wheels by a resilient suspension system. The structures of body and frame assemblies can be divided into two general categories, namely separate and unitized. In a typical separate body and frame assembly, the structural components of the vehicle body and the vehicle frame assembly are separate and independent from one another. When assembled, the vehicle frame assembly is resiliently supported on the vehicle wheels by the suspension system and serves as a platform on which the vehicle body and other components of the vehicle can be mounted. Separate body and frame assemblies of this general type are found in most older vehicles, but remain in common use today for many relatively large or specialized modem vehicles, such as trucks, large vans and sport utility vehicles. In a typical unitized body and frame assembly, the structural components of the vehicle body and the vehicle frame assembly are combined into an integral unit which is resiliently supported on the vehicle wheels by the suspension system. Unitized body and frame assemblies of this general type are found in many relatively small modem vehicles, such as automobiles and minivans.
In both types of body and frame assemblies, the vehicle frame assembly usually includes a pair of elongated, parallel side rails, and a plurality of cross members extending between the side rails to connect them together. In the past, these structural components of the vehicle frame assembly have usually been formed of steel. Vehicle frame components formed of steel provide desirable strength and stiffness to the vehicle frame assembly. However, the steel vehicle frame components are relatively heavy and, therefore, undesirably add to the weight of the vehicle. It is known to form some kinds of vehicle components from fiber-reinforced synthetic resins. The fiber-reinforced resins are significantly lighter than steel, but they generally do not have sufficient strength for use as vehicle frame components in heavy vehicles. Accordingly, it would be advantageous to provide a method of manufacturing a lightweight vehicle frame component having excellent strength and stiffness.